Wiper Barrier Plug Assemblies

ABSTRACT

A wiper barrier plug assembly can include a wiper plug, an expandable plug, and a trigger device that includes a trigger that is communicably coupled to the expandable plug, where the wiper plug, the expandable plug, and the trigger device are coupled to each other. The trigger device can be configured to detect a trigger condition while the trigger device is pumped down a cavity of the casing string. The trigger device can also be configured to operate, upon detecting the trigger condition, the expandable plug from a default position to an expanded position, where the expandable plug, when in the expanded position, is configured to abut against an inner surface of the casing string and to prevent the expandable plug from moving relative to the casing string.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application Ser. No. 63/122,744 titled “Wiper Barrier Plug Assemblies” and filed on Dec. 8, 2020, the entire contents of which are hereby incorporated herein by reference.

TECHNICAL FIELD

The present application is related to wellbore operations and, more particularly, to count and set wiper barrier plug assemblies for use in wellbore cementing operations.

BACKGROUND

During drilling and completions operations of a hydrocarbon producing wellbore, well casing is typically run to a desired depth while drilling a wellbore, and then cement is generally used to solidify the casing within the drilled wellbore. During the cementing operation, a cement slurry is pumped through the inner bore of the well casing, out its distal end, and into the annulus formed between the well casing and the wellbore. The cement is then pumped back up toward the surface within the annulus. Once the cement hardens, the cement bonds the well casing to the surrounding rock formation to provide support and strength to the well casing. In addition, the hardened cement forms a seal between the well casing and the wellbore to protect oil-producing zones and non-oil-producing zones from contamination.

Currently, primary cement jobs utilize volume to verify displacement of a rubber cementing plug (commonly referred to as a top plug) after pumping all the designed cement. During the cementing operation, a lead plug (also called a bottom plug), which is rupturable, isolates drilling fluid or mud in the casing from the cement slurry. After the cement volume is pumped, a tail plug (also called a wiper plug), which is solid, is utilized to separate the cement from a displacement fluid, such as displacement mud. There is a float at the bottom of the casing string that acts as a plug. If the float does not hold, then a wireline operation can be performed to set a temporary bridge plug above the tail plug in the well, which generally adds to rig time and conveyance expense. In addition, in some instances, the cement volume pumped may not be enough due to uncertainty of the placement of the tail plug within the wellbore.

Prior to cementing, the wellbore and the well casing are typically filled with drilling fluid or mud. A bottom wiper plug is then pumped ahead of the spacer fluid followed by the cement slurry in order to prevent mixing of the drilling mud already present within the wellbore with the cement slurry. When the bottom wiper plug reaches a float or landing collar or cement plug arranged within the casing at a predetermined location, the hydraulic pressure of the cement slurry ruptures the burst disk of the bottom wiper plug and enables the cement slurry to pass through the plug and then through either the distal end of the casing or the side ports and into the annulus. Once all of the cement volumes are pumped at the surface, a top wiper plug is pumped down the casing to prevent mixing of the cement slurry with displacement fluid that will be pumped into the casing following the cement slurry. When the top wiper plug lands on the bottom wiper plug or the landing/float collar, the pumping of the displacement fluid ceases. Pressure responses at the surface or volume calculations are used to determine the landing of the top wiper plug. Typically, the floats and casing are tested separately to determine mechanical integrity and wellbore isolation to/from the annuli. If mechanical integrity is not achieved, operations may require a wireline plug to be set to continue subsequent drilling operations or may require waiting on cement to set to achieve isolation to the surface.

Prior to, during, and following the cementing operation, it may prove advantageous to monitor and transmit various wellbore parameters relating to the cementing operation to ensure that operations are proceeding and completed as designed.

SUMMARY

In general, in one aspect, the disclosure relates to wiper barrier plug assembly that includes a wiper plug having a wiper plug body and a plurality of wipers extending from the wiper plug body, where the plurality of wipers is configured to contact an inner surface of a casing string disposed in a wellbore. The wiper barrier plug assembly can also include an expandable plug and a trigger device having a trigger that is communicably coupled to the expandable plug, where the wiper plug, the expandable plug, and the trigger device are mechanically coupled together. The trigger device can be configured to detect a trigger condition while the trigger device is pumped down a cavity of the casing string formed by the inner surface. The trigger device can also be configured to operate, upon detecting the trigger condition, the expandable plug from a default position to an expanded position, where the expandable plug, when in the expanded position, is configured to abut against an inner surface of the casing string and to prevent the expandable plug from moving relative to the casing string.

In another aspect, the disclosure relates to a system for preparing a casing string in a wellbore for cement. The system can include a landing assembly disposed at a distal end of the casing string, where the landing assembly provides a channel for a first fluid to flow from a cavity of the casing string toward the surface through an annulus formed between an outer surface of the casing string and a wellbore wall. The system can also include a bottom plug affixed to an inner surface of the casing string above the landing assembly, where the bottom plug has a flow path that traverses therethrough and through which the first fluid flows. The system can further include a wiper barrier plug assembly disposed in the cavity of the casing string. The wiper barrier plug assembly can include a wiper plug having a wiper plug body and a plurality of wipers, where the wiper plug provides a barrier between a first fluid disposed below the wiper plug and a second fluid disposed above the wiper plug. The wiper barrier plug assembly can also include an expandable plug operable from a default position and an expanded position. The wiper barrier plug assembly can further include a trigger device that includes a trigger, where the wiper plug, the expandable plug, and the trigger device are mechanically coupled together. The trigger device can detect a trigger condition while the wiper barrier plug assembly is pumped toward the bottom plug by a pumping system. The trigger device can also operate, upon detecting the trigger condition, the expandable plug from the default position to the expanded position, where the expandable plug, when in the expanded position, is configured to abut against the inner surface of the casing string prevents the expandable plug from moving relative to the casing string.

In yet another aspect, the disclosure relates to a method for setting a wiper barrier plug assembly when cementing a casing string in a wellbore. The method can include detecting, by a trigger device of the wiper barrier plug assembly, a trigger condition while the wiper barrier plug assembly is pumped through a cavity of the casing string toward the bottom plug by a pumping system. The method can also include operating, by the trigger device upon detecting the trigger condition, an expandable plug of the wiper barrier plug assembly from a default position to an expanded position, where the expandable plug, when in the expanded position, abuts against an inner surface of the casing string and prevents the wiper barrier plug assembly from moving relative to the casing string, where the wiper plug, the expandable plug, and the trigger device are coupled to each other.

These and other aspects, objects, features, and embodiments will be apparent from the following description and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate only example embodiments and are therefore not to be considered limiting in scope, as the example embodiments may admit to other equally effective embodiments. The elements and features shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the example embodiments. Additionally, certain dimensions or positions may be exaggerated to help visually convey such principles. In the drawings, reference numerals designate like or corresponding, but not necessarily identical, elements.

FIG. 1 shows a system for performing a wellbore cementing operation in which example embodiments can be used.

FIGS. 2 through 4 show a cross-sectional view of a subsystem that includes a wiper barrier plug assembly used in a wellbore cementing operation according to certain example embodiments.

FIGS. 5 through 7 show a cross-sectional view of a subsystem that includes another wiper barrier plug assembly used in a wellbore cementing operation according to certain example embodiments.

FIGS. 8 through 10 show a cross-sectional view of a subsystem that includes yet another wiper barrier plug assembly used in a wellbore cementing operation according to certain example embodiments.

FIG. 11 shows a diagram of a system of a wiper barrier plug assembly according to certain example embodiments.

FIG. 12 shows a computing device according to certain example embodiments.

DESCRIPTION OF THE INVENTION

The example embodiments discussed herein are directed to systems, methods, and devices for wiper barrier plug assemblies and related systems for wellbore cementing operations. Wellbores that undergo cementing operations for which example embodiments are used can be drilled and completed to extract a subterranean resource. Examples of a subterranean resource can include, but are not limited to, natural gas, oil, steam, and water. Wellbores for which example embodiments are used for cementing operations can be land-based or subsea. Example embodiments of wiper barrier plug assemblies can be rated for use in hazardous environments.

An example wiper barrier plug assembly includes multiple components that are described herein, where a component can be made from a single piece (as from a mold or an extrusion). When a component (or portion thereof) of an example wiper barrier plug assembly is made from a single piece, the single piece can be cut out, bent, stamped, and/or otherwise shaped to create certain features, elements, or other portions of the component. Alternatively, a component (or portion thereof) of an example wiper barrier plug assembly can be made from multiple pieces that are mechanically coupled to each other. In such a case, the multiple pieces can be mechanically coupled to each other using one or more of a number of coupling methods, including but not limited to adhesives, welding, fastening devices, compression fittings, mating threads, and slotted fittings. One or more pieces that are mechanically coupled to each other can be coupled to each other in one or more of a number of ways, including but not limited to fixedly, hingedly, rotatably, removably, slidably, and threadably.

Components and/or features described herein can include elements that are described as coupling, fastening, securing, or other similar terms. Such terms are merely meant to distinguish various elements and/or features within a component or device and are not meant to limit the capability or function of that particular element and/or feature. For example, a feature described as a “coupling feature” can couple, secure, abut against, fasten, and/or perform other functions aside from merely coupling. In addition, each component and/or feature described herein (including each component of an example wiper barrier plug assembly) can be made of one or more of a number of suitable materials, including but not limited to metal (e.g., stainless steel), ceramic, rubber, glass, and plastic.

A coupling feature (including a complementary coupling feature) as described herein can allow one or more components (e.g., a housing) and/or portions of an example wiper barrier plug assembly to become mechanically coupled, directly or indirectly, to another portion of the wiper barrier plug assembly and/or a component (e.g., a casing pipe) of a casing string. A coupling feature can include, but is not limited to, a portion of a hinge, an aperture, a recessed area, a protrusion, a slot, a spring clip, a tab, a detent, and mating threads. One portion of an example wiper barrier plug assembly can be coupled to another portion of the wiper barrier plug assembly and/or a component of casing string by the direct use of one or more coupling features.

In addition, or in the alternative, a portion of an example wiper barrier plug assembly can be coupled to another portion of the wiper barrier plug assembly and/or a component of a casing string using one or more independent devices that interact with one or more coupling features disposed on a component of the wiper barrier plug assembly. Examples of such devices can include, but are not limited to, a pin, a hinge, a fastening device (e.g., a bolt, a screw, a rivet), an adapter, and a spring. One coupling feature described herein can be the same as, or different than, one or more other coupling features described herein. A complementary coupling feature as described herein can be a coupling feature that mechanically couples, directly or indirectly, with another coupling feature.

When used in certain systems (e.g., for certain subterranean field operations), example embodiments can be designed to help such systems comply with certain standards and/or requirements. Examples of entities that set such standards and/or requirements can include, but are not limited to, the Society of Petroleum Engineers, the American Petroleum Institute (API), the International Standards Organization (ISO), and the Occupational Safety and Health Administration (OSHA). Also, as discussed above, example wiper barrier plug assemblies can be used in hazardous environments, and so example wiper barrier plug assemblies can be designed to comply with industry standards that apply to hazardous environments.

If a component of a figure is described but not expressly shown or labeled in that figure, the label used for a corresponding component in another figure can be inferred to that component. Conversely, if a component in a figure is labeled but is not described, the description for such component can be substantially the same as the description for the corresponding component in another figure. The numbering scheme for the various components in the figures herein is such that each component is a three-digit number or a four-digit number and corresponding components in other figures have the identical last two digits. For any figure shown and described herein, one or more of the components may be omitted, added, repeated, and/or substituted. Accordingly, embodiments shown in a particular figure should not be considered limited to the specific arrangements of components shown in such figure.

Further, a statement that a particular embodiment (e.g., as shown in a figure herein) does not have a particular feature or component does not mean, unless expressly stated, that such embodiment is not capable of having such feature or component. For example, for purposes of present or future claims herein, a feature or component that is described as not being included in an example embodiment shown in one or more particular drawings is capable of being included in one or more claims that correspond to such one or more particular drawings herein.

Example embodiments of wiper barrier plug assemblies and related systems for wellbore cementing operations will be described more fully hereinafter with reference to the accompanying drawings, in which example embodiments of wiper barrier plug assemblies and related systems for wellbore cementing operations are shown. Wiper barrier plug assemblies and related systems for wellbore cementing operations may, however, be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of wiper barrier plug assemblies and related systems for wellbore cementing operations to those of ordinary skill in the art. Like, but not necessarily the same, elements (also sometimes called components) in the various figures are denoted by like reference numerals for consistency.

Terms such as “first”, “second”, “outer”, “inner”, “top”, “bottom”, “distal”, “proximal”, “above”, “below”, “upper”, “lower”, “left”, “right”, “front”, “rear”, “end”, “side”, “on”, and “within”, when present, are used merely to distinguish one component (or part of a component or state of a component) from another. This list of terms is not exclusive. Such terms are not meant to denote a preference or a particular orientation, and they are not meant to limit embodiments of wiper barrier plug assemblies and related systems for wellbore cementing operations. In the following detailed description of the example embodiments, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

FIG. 1 shows a system for performing a wellbore 122 cementing operation in which example embodiments can be used. The wellbore 122 of the field system 100 in this example is disposed in a subterranean formation 110. The wellbore 122 is defined by a wall 109. The wellbore 122 is drilled using field equipment (e.g., a derrick, a tool pusher, a clamp, a tong, drill pipe, casing pipe, a drill bit, and a fluid pumping system). Some of this equipment is located above a surface 108 and within the wellbore 122 as the wellbore 122 is drilled. Once the wellbore 122 (or a section thereof) is drilled, a casing string 115 is inserted into the wellbore 122 and subsequently cemented to the wall 109 of the wellbore 122 to stabilize the wellbore 122 and allow for the extraction of subterranean resources (e.g., oil, natural gas) from the subterranean formation 110 through the wellbore 122.

The surface 108 can be ground level for an on-shore (also called land-based) application (as in this case) and the sea floor for an off-shore application. The point where the wellbore 122 begins at the surface 108 can be called the entry point. While not shown in FIG. 1, there can be multiple wellbores 122, each with their own entry point but that are located close to the other entry points, drilled into the subterranean formation 110. In such a case, the multiple wellbores 122 can be drilled at the same pad location.

The subterranean formation 110 can include one or more of a number of formation types, including but not limited to shale, limestone, sandstone, clay, sand, and salt. In certain embodiments, a subterranean formation 110 can include one or more reservoirs in which one or more resources (e.g., oil, gas, water, steam) can be located. One or more of a number of field operations (e.g., fracking, coring, tripping, drilling, setting casing, extracting downhole resources) can be performed to reach an objective of a user with respect to the subterranean formation 110.

The wellbore 122 can have one or more of a number of segments, where each segment can have one or more of a number of dimensions. Examples of such dimensions can include, but are not limited to, size (e.g., diameter) of the wellbore 122, a curvature of the wellbore 122, a total vertical depth of the wellbore 122, a measured depth of the wellbore 122, and a horizontal displacement of the wellbore 122. A wellbore 122 can also undergo multiple cementing operations, where each cementing operation covers part or all of a segment of the wellbore 122 or multiple segments of the wellbore 122.

As discussed above, inserted into and disposed within the wellbore 122 of FIG. 1 is a casing string 115. The casing string 115 includes a number of casing pipes that are coupled to each other end-to-end to form the casing string 115. Each end of a casing pipe has mating threads (a type of coupling feature) disposed thereon, allowing a casing pipe to be mechanically coupled to a casing pipe in an end-to-end configuration. The casing pipes of the casing string 115 can be mechanically coupled to each other directly or indirectly using a coupling device, such as a coupling sleeve.

Each casing pipe of the casing string 115 can have a length and a width (e.g., outer diameter). The length of a casing pipe can vary. For example, a common length of a casing pipe is approximately 40 feet. The length of a casing pipe can be longer (e.g., 60 feet) or shorter (e.g., 10 feet) than 40 feet. The width of a casing pipe can also vary and can depend on the cross-sectional shape of the casing pipe. For example, when the cross-sectional shape of a casing pipe is circular, which is commonly the case, the width can refer to an outer diameter, an inner diameter, or some other form of measurement of the casing pipe. Examples of a width in terms of an outer diameter of a casing pipe can include, but are not limited to, 4½ inches, 7 inches, 7⅝ inches, 8⅝ inches, 10¾ inches, 13⅜ inches, and 14 inches. Typically, the larger widths of the casing pipe are closer to the entry point at the surface 108, and the width gradually decreases by segment moving toward the distal end of the wellbore 122.

The size (e.g., width, length) of the casing string 115 can be based on the information gathered using field equipment with respect to the subterranean wellbore 122. The walls of the casing string 115 have an inner surface that forms a cavity 120 that traverses the length of the casing string 115. Each casing pipe of the casing string 115 can be made of one or more of a number of suitable materials, including but not limited to stainless steel. In some cases, a casing pipe of the casing string 115 can have a collar (such as the collars 205 of FIG. 2 below). There is a gap 195, also called an annulus 195, between the outer surface of the casing string 115 and the wall 109 of the wellbore 122. In some cases, stabilizers (not shown) or similar devices can be inserted along with the casing pipes and/or integrated with the casing pipe. These stabilizers help to keep the casing string 115 relatively centered within the wellbore 122.

The goal of a cementing operation is to put wet cement in the annulus 195 to dry and harden. Specialized equipment 190, positioned at the surface 108 near the entry point of the wellbore 122, can be used in a subterranean cementing operation. Such equipment 190 can include, but is not limited to, mixers, pumps, storage tanks, motors, generators, and piping. When the cement sets and dries, a secure bond is created between the subterranean formation 110 (at the wall 109) and the casing string 115. Typically, a cement slurry is poured or pumped into the cavity 120 of the casing string 115 using the equipment 190, and then the cement slurry is forced at the bottom of the casing string 115 upward into the annulus 195. Example embodiments can be used to ensure that a cementing operation is effectively and efficiently executed relative to cementing operations performed in the current art.

FIGS. 2 through 4 show a cross-sectional view of a subsystem that includes a wiper barrier plug assembly 250 used in a wellbore cementing operation according to certain example embodiments. Referring to FIGS. 1 through 4, the subsystem 299 of FIG. 2 shows a point in time during the wellbore cementing operation. The subsystem 399 of FIG. 3 shows a subsequent point in time during the wellbore cementing operation relative to the time shown in FIG. 2. The subsystem 499 of FIG. 4 shows a subsequent point in time during the wellbore cementing operation relative to the time shown in FIG. 3. Each of the subsystems of FIGS. 2 through 4 include the example wiper barrier plug assembly 250 disposed within the cavity 220 of a casing string 215, where the casing string 215 is disposed in a wellbore 222.

In this case, the casing string 215, which is substantially the same as the casing string 115 of FIG. 1, is already inserted into the wellbore 222, which is substantially the same as the wellbore 122 of FIG. 1. For example, the wellbore 222 is defined by a wall 209 and is drilled into a subterranean formation 210. Also, in this case, at least some of the casing pipes of the casing string 215 have collars 205. In certain example embodiments, these collars 205 have a characteristic (e.g., larger thickness, different (e.g., magnetic, radioactive) material, an added device (e.g., radio frequency identification tag (RFID))) that differs from the rest of the casing string 215. As explained below, this different characteristic of the collars 205 can be used by the trigger device 270 of the example wiper barrier plug assembly 250 to determine when the expandable plug 260 should be operated from a default position to an engaged position.

The point in time during the wellbore cementing operation in FIG. 2 is after a float shoe 235 has been set at or below the bottom of the casing string 215 within the wellbore 222. The float shoe 235 allows fluids (e.g., the cement slurry 211) to flow, with sufficient downward pressure from within the cavity 220, from within the cavity 220 back up through the annulus 295. In addition, after the float shoe 235 has been set, one or more landing collars 230 can be set within the cavity 220 of the casing string 215. If there are multiple landing collars 230, the most distal one (or in the case of a single landing collar 230, the only one) is set some distance (e.g., 30 feet, 40 feet, 60 feet) above the float shoe 235. If there are multiple landing collars 230, the spacing between them can vary. The one or more landing collars 230 act as a one-way valve that allows fluids to flow down the cavity 220 but not back up the cavity 220. In some cases, the combination of the float shoe 235 and the landing collar(s) 230 can be defined as a landing assembly.

After all of the landing collars 230 are set within the cavity 220 of the casing string 215, chemical washes and spacing fluids are inserted into the cavity 220 of the casing string 215. Next, the bottom plug 240 is inserted within the cavity 220 of the casing string 215. The spacing between the proximal-most landing collar 230 (or the only landing collar 230) and the bottom plug 240 can vary. The bottom plug 240 has a body 242 from which multiple wipers 245 extend outward. The wipers 245 are designed to abut against the inner surface of the casing string 215 and wipe any debris and/or chemicals off of the inner surface of the casing string 215 and push any such debris and/or chemicals downhole within the cavity 220 so that the cement slurry 211, once it occupies that space within the cavity 220, does not become contaminated.

When the bottom plug 240 is put in position within the cavity 220 (e.g., abutting against the top of the proximal-most landing collar 230), a cement slurry 211 is inserted (pumped, dumped) into the cavity 220 of the casing string 215 from the surface 108. When the pressure applied by the cement slurry 211 against the top of the bottom plug 240 is great enough, a rupture disc (or other mechanical mechanism, such as a diaphragm) can be broken, which opens a passage 244 along the height of the body 242 of the bottom plug 240. With the rupture disc broken, the cement slurry 211 can pass through the passage 244 in the bottom plug 240. Once the prepared volume of the cement slurry 211 is inserted into the cavity 220 of the casing string 215, the example wiper barrier plug assembly 250 is inserted atop the cement slurry 211 in the cavity 220 of the casing string 215, and displacement fluid 212 is subsequently pumped down (e.g., using equipment 190) atop the wiper barrier plug assembly 250.

The example wiper barrier plug assembly 250 is designed to push the cement slurry 211 down the cavity 220, eventually forcing the cement slurry 211 up the annulus 295 before the cement slurry 211 sets and hardens. The example wiper barrier plug assembly 250 is also designed to automatically fix its position at the proper location within the cavity 220 without the need to use a wireline tool and/or other similar equipment. As a result, example embodiments save time, money, and other resources relative to the current art during wellbore cementing operations.

In certain example embodiments, the wiper barrier plug assembly 250 includes multiple components that are mechanically coupled together. For example, in this case, the wiper barrier plug assembly 250 includes a wiper plug 280, a trigger device 270, and an expandable plug 260. These multiple components are mechanically coupled to each other, directly or indirectly, in any of a number of ways using any of a number of coupling features (e.g., mating threads, fastening devices, slotted fittings, compression fittings, welding). In certain example embodiments, the multiple components of the wiper barrier plug assembly 250 are arranged vertically with respect to each other, as shown in FIGS. 2 through 4. The arrangement of the components of the wiper barrier plug assembly 250 can vary. For example, as the wiper barrier plug assembly 250 of FIG. 2 shows, the expandable plug 260 can be placed atop and coupled to the trigger device 270, which is placed atop and coupled to the wiper plug 280. Any other order (e.g., the wiper plug 280 on top, the trigger device 270 on the bottom) can be used without affecting the functionality of each component or the wiper barrier plug assembly 250 as a whole.

The wiper plug 280 (also known by other names in the art, such as a top wiper plug) of the wiper barrier plug assembly 250 is configured to have a body 282 from which multiple wipers 285 extend outward. The wipers 285 are designed to abut against the inner surface of the casing string 215 and wipe any cement slurry 211 off of the inner surface of the casing string 215 and push the cement slurry 211 downhole within the cavity 220. The wipers 285 of the wiper plug 280 are also oriented upward and have some amount of stiffness. In this way, as the wiper barrier plug assembly 250 is pumped down the cavity 220 ahead of the displacement fluid 212, none of the displacement fluid 212 is able to pass around the wipers 285 to mix with the cement slurry 211. Also, the body 282 of the wiper plug 280 is solid (e.g., does not have a cavity that traverses therethrough), and so the wiper plug 280 does not degrade or change state in such a way that allows the displacement fluid 212 to flow through and/or around the wiper plug 280 to mix with the cement slurry 211.

The expandable plug 260 of the wiper barrier plug assembly 250 is designed to set and seal across the inner surface of the casing string 215 at an appropriate depth in the wellbore 222. The expandable plug 260 can have any of a number of configurations. For example, the expandable plug 260 can be a cast iron bridge plug. As another example, the expandable plug 260 can be a composite plug. In any case, the expandable plug 260 has a default position (as shown in FIGS. 2 and 3) and an expanded position (as shown in FIG. 4). In the default position, the expandable plug 260 avoids contact with the inner surface of the casing string 215 as the wiper barrier plug assembly 250 is moved down the cavity 220.

In the expanded position, the expandable plug 260 extends outward in all directions so that the expandable plug 260 abuts against and creates a seal with the inner surface of the casing string 215. In so doing, the expandable plug 260 becomes fixed in place within the cavity 220 relative to the casing string 215. The trigger device 270 of the wiper barrier plug assembly 250 operates the expandable plug 260 from the default position to the expanded position, and so the trigger device 270 is communicably coupled to the expandable plug 260 to initiate such operation. In certain example embodiments, the expandable plug 260 has bi-directional slips so that, when in the expanded position, the expandable plug 260 remains in place relative to the casing string 215, even when differential pressure from above and/or below the wiper barrier plug assembly 250 within the cavity 220 exists.

The trigger device 270 of the wiper barrier plug assembly 250 is configured to determine when a trigger condition is met and, if so, operate the expandable plug 260 into the expanded position. The trigger condition can be based on one or more of a number of factors, including but not limited to a parameter measured by a sensor device and time. The trigger device 270 can include one or more of a number of components. Examples of such components can include, but are not limited to, a sensor device, a timer, and a controller. In certain example embodiments, the trigger device 270 has a housing 272 that encloses one or more of the components of the trigger device 270. An example of a trigger device 270 and its various components (e.g., a sensor device) is shown below with respect to FIG. 11.

The equipment (e.g., equipment 190) used to pump the displacement fluid 212 (and so also the wiper barrier plug assembly 250) down the cavity 220 of the casing string 215 can make adjustments based on certain conditions during a subterranean cementing operation. For example, when the wiper barrier plug assembly 250 is within a certain distance (e.g., 200 feet) of reaching the bottom plug 240, the pump rate can be reduced to slow the velocity at which the wiper barrier plug assembly 250 travels the remaining distance until the trigger condition is detected by the trigger device 270 of the wiper barrier plug assembly 250. Such conditions can be based on measurements made by sensor devices (e.g., of the trigger device 270), estimates (e.g., volume of displacement fluid 212 pumped compared to volume of the cavity 220 above the bottom plug 240), and/or any other factor.

In this example captured in FIGS. 2 through 4, the trigger condition occurs after a certain number of collars 205 have been identified as the wiper barrier plug assembly 250 travels down the cavity 220. For example, the trigger device 270 can include a sensor device (e.g., a sensor device 1178 of FIG. 11) that measures the thickness of the casing string 215 and identifies each collar 205 because of its pronounced added thickness relative to the thickness of the rest of the casing string 215. As another example, the trigger device 270 can include a sensor device (e.g., another sensor device 1178 of FIG. 11) that measures a magnetic field. In such a case, the sensor device of the trigger device 270 can identify each collar 205 because of its pronounced difference (e.g., in terms of strength, in terms of polarity) in the magnetic field it emits relative to the magnetic field emitted by the rest of the casing string 215. The magnetic field in a collar 205 can be part of the natural manufacturing process or artificially added (e.g., by the manufacturer, in the field).

In any case, the trigger device 270 can include a controller (e.g., the controller 1174 of FIG. 11) and a counter (e.g., the counter 1177 of FIG. 11) that are in communication with the sensor device (e.g., a sensor device 1178 of FIG. 11). The controller can receive the measurement, evaluate the measurement (e.g., determine if the measurement exceeds some parameter threshold value that indicates whether the characteristic within the casing string 215 has been encountered), and if the evaluation shows that the characteristic within the casing string 215 has been encountered, increment a count of the counter. The controller can also determine whether the counter, after having been incremented, exceeds a count threshold value. As of the time during the subterranean cementing operation captured in FIG. 2, one collar 205 has been counted by the trigger device 270, and the wiper barrier plug assembly 250 has forced the cement slurry 211 only a small way up the annulus 295.

In some optional embodiments, the trigger device 270 of the example wiper barrier plug assembly 250 can also include a back-up trigger 275. The back-up trigger 275 can force the expandable plug 260 to operate from the default position to the expanded position if there is some malfunction of one or more of the primary components (e.g., a sensor device, the controller, the counter). The back-up trigger 275 can take on any of a number of forms and/or have any of a number of components. For example, the back-up trigger 275 can include a timer that measures a threshold amount of time by which the trigger condition needs to occur. In any case, if the expandable plug 260 has not operated by the time that the back-up trigger 275 reaches or exceeds its threshold value, then the back-up trigger 275 can be configured to operate the expandable plug 260 into the expanded position.

The subsystem 399 of FIG. 3, which captures some amount of time (e.g., 10 seconds) after the time captured by the subsystem 299 of FIG. 2, includes all of the same components of the subsystem 299 of FIG. 2. At the point in time captured in FIG. 3, the wiper barrier plug assembly 250, propelled by the displacement fluid 212 pumped into the cavity 220 within the casing string 215, is located closer to the bottom plug 240. As a result, the cement slurry 211 is pushed further up the annulus 295. Also, the trigger device 270 has identified and counted another collar 205 to bring the total to 2. Since a count of 2 equals but does not exceed the count threshold value (which in this case is 2), the expandable plug 260 remains in the default position, allowing the wiper barrier plug assembly 250 to continue traveling down the cavity 220.

The subsystem 499 of FIG. 4, which captures some amount of time (e.g., 5 seconds) after the time captured by the subsystem 399 of FIG. 3, includes all of the same components of the subsystem 399 of FIG. 3. At the point in time captured in FIG. 4, the wiper barrier plug assembly 250, further propelled by the displacement fluid 212 pumped into the cavity 220 within the casing string 215, is located just above, if not abutting against, the bottom plug 240. As a result, the cement slurry 211 is pushed even further up the annulus 295. More importantly, the trigger device 270, having just passed a third collar 205, which was identified and counted by the components (e.g., a sensor device, a controller, a counter) of the trigger device 270, has operated the expandable plug 260 from the default position to the expanded position. This action was taken because the count threshold value of 2 became exceeded.

By operating the expandable plug 260 into the expanded position, the expandable plug 260 extends outward in all directions so that the expandable plug 260 abuts against and creates a seal with the inner surface of the casing string 215. In so doing, the expandable plug 260 becomes fixed in place within the cavity 220 relative to the casing string 215. In some cases, the expandable plug 260 in its expanded position creates a pressure barrier and can remain anchored in place in spite of any pressure differential that may exist between the cavity 220 above the wiper barrier plug assembly 250 and in the cavity 220 below the wiper barrier plug assembly 250. Additionally, or alternatively, one or more other parts (e.g., the wipers 285 of the wiper plug 280) of the wiper barrier plug assembly 250 can create a pressure barrier and can remain fixed in place in spite of any pressure differential that may exist between the cavity 220 above the wiper barrier plug assembly 250 and in the cavity 220 below the wiper barrier plug assembly 250.

When the expandable plug 260 is operated into the expanded position by the trigger device 270, a pressure spike through the displacement fluid 212 above the wiper barrier plug assembly 250 within the cavity 220 can be measured at the surface (e.g., surface 108) by equipment (e.g., equipment 190). When the pressure spike is registered, the equipment pumping the displacement fluid 212 into the cavity 220 can be shut down. Also, one or more tests (e.g., a casing test, an in-flow test) can be performed at the surface (e.g., surface 108) using other equipment (e.g., part of equipment 190) to confirm that the expandable plug 260 of the wiper barrier plug assembly 250 is continuing to hold pressure.

In certain example embodiments, the wiper plug 280 can be modified to enable example embodiments. For example, a load cell can be inserted into a bottom surface of the body 282 of the wiper plug 280. In such a case, the wiper plug 280 can be placed at the bottom of the wiper barrier plug assembly 250. In this way, when the wiper plug 280 abuts against the bottom plug 240, and when the pumps are still running (whereby the displacement fluid 212 applies a downward force against the wiper plug 280 that is accentuated by the immovable bottom plug 240), the controller of the trigger device 270 can trigger the operation of the expandable plug 260 based on the load cell reading a weight that exceeds a threshold value. In this configuration, the load cell could act as the primary driver for the trigger condition or as the back-up trigger 275.

In certain example embodiments, the controller of the trigger device 270 (or some other component of the wiper barrier plug assembly 250) can communicate with a controller (e.g., part of the equipment 190) at the surface (e.g., surface 108). In such a case, the controller of the trigger device 270 (or other component of the wiper barrier plug assembly 250) can send data to the controller at the surface. In addition, or in the alternative, a controller at the surface can send signals to the controller of the trigger device 270 to operate the trigger device 270. These communications can be facilitated in any manner (e.g., using an electrical cable, using waves transmitted through the displacement fluid 212) known in the art.

FIGS. 5 through 7 show a cross-sectional view of a subsystem that includes another wiper barrier plug assembly 550 used in a wellbore cementing operation according to certain example embodiments. Referring to FIGS. 1 through 7, the subsystem 598 of FIG. 5 shows a point in time during the wellbore cementing operation. The subsystem 698 of FIG. 6 shows a subsequent point in time during the wellbore cementing operation relative to the time shown in FIG. 5. The subsystem 798 of FIG. 7 shows a subsequent point in time during the wellbore cementing operation relative to the time shown in FIG. 6.

Many of the components of the subsystem 598 of FIG. 5 are substantially similar to the corresponding components of the subsystem 299 of FIG. 2, except as discussed below. For example, the subsystem 598 of FIG. 5 includes a casing string 515 inserted into a wellbore 522. The wellbore 522 is defined by a wall 509 and is drilled into a subterranean formation 510. Also, in this case, at least some of the casing pipes of the casing string 515 have collars 505. The subsystem 598 of FIG. 5 also includes a float shoe 535 that has been set at or below the bottom of the casing string 515 within the wellbore 522, and one or more landing collars 530 that are set within the cavity 520 of the casing string 515 above the float shoe 535. All of these components (e.g., the float shoe 535, the collars 505, the landing collar 530) are substantially the same as the corresponding components (e.g., the float shoe 235, the collars 205, the landing collar 230) discussed above.

The subsystem 598 of FIG. 5 also includes a bottom plug 540 that is inserted within the cavity 520 of the casing string 515. The bottom plug 540 can be substantially the same as the bottom plug 240 discussed above. For example, the bottom plug 540 has a body 542 from which multiple wipers 545 extend outward. Also, the rupture disc (or other mechanical mechanism, such as a diaphragm) of the bottom plug 540 can break, as shown in FIG. 5, which opens a passage 544 along the height of the body 542 of the bottom plug 540. With the rupture disc broken, the cement slurry 511 can pass through the passage 544 in the bottom plug 540. Once the prepared volume of the cement slurry 511 is inserted into the cavity 520 of the casing string 515, the example wiper barrier plug assembly 550 is inserted atop the cement slurry 511 in the cavity 520 of the casing string 515, and displacement fluid 512 is subsequently pumped down (e.g., using equipment 190) atop the wiper barrier plug assembly 550.

The example wiper barrier plug assembly 550 is designed to push the cement slurry 511 down the cavity 520, eventually forcing the cement slurry 511 up the annulus 595 before the cement slurry 511 sets and hardens. As with the wiper barrier plug assembly 250 above, the wiper barrier plug assembly 550 of FIG. 5 includes a wiper plug 580, a trigger device 570, and an expandable plug 560. These multiple components are coupled to each other in any of a number of ways. In certain example embodiments, the multiple components of the wiper barrier plug assembly 550 are arranged vertically with respect to each other, as shown in FIGS. 5 through 7, but the arrangement of the components of the wiper barrier plug assembly 550 can vary.

The wiper plug 580 and the expandable plug 560 of the wiper barrier plug assembly 550 are substantially the same as the wiper plug 280 and the expandable plug 260 of the wiper barrier plug assembly 250. For example, the wiper plug 580 includes a body 582 from which multiple wipers 585 extend outward. The wipers 585 of the wiper plug 580 are oriented upward and have some amount of stiffness. In this way, as the wiper barrier plug assembly 550 is pumped down the cavity 520 ahead of the displacement fluid 512, none of the displacement fluid 512 is able to pass around the wipers 585 to mix with the cement slurry 511. Also, the body 582 of the wiper plug 580 is solid (e.g., does not have a cavity that traverses therethrough), and so the wiper plug 580 does not degrade or change state in such a way that allows the displacement fluid 512 to flow through and/or around the wiper plug 580 to mix with the cement slurry 511.

Also, the expandable plug 560 of the wiper barrier plug assembly 550 has a default position (as shown in FIGS. 5 and 6) and an expanded position (as shown in FIG. 7). In the default position, the expandable plug 560 avoids contact with the inner surface of the casing string 515 as the wiper barrier plug assembly 550 is moved down the cavity 520. In the expanded position, the expandable plug 560 extends outward in all directions so that the expandable plug 560 abuts against and creates a seal with the inner surface of the casing string 515. In so doing, the expandable plug 560 becomes fixed in place within the cavity 520 relative to the casing string 515. The trigger device 570 operates the expandable plug 560 from the default position to the expanded position, and so the trigger device 570 is communicably coupled to the expandable plug 560 to initiate such operation. In certain example embodiments, the expandable plug 560 has bi-directional slips so that, when in the expanded position, the expandable plug 560 remains in place relative to the casing string 515, even when differential pressure from above and below the wiper barrier plug assembly 550 within the cavity 520 exists.

The trigger device 570 of the wiper barrier plug assembly 550 is configured to determine when a trigger condition is met and, if so, operate the expandable plug 560 into the expanded position. The trigger device 570 has a housing 572 that encloses one or more of the components (e.g., a sensor device, a controller) of the trigger device 570. As stated above, an example of a trigger device 570 and its various components is shown below with respect to FIG. 11. While there are 2 collars 505 in this example, the sensor device of the trigger device 570 is ignoring them. In this example captured in FIGS. 5 through 7, the trigger condition occurs when a tag 525 (e.g., a RFID tag) embedded in or disposed on a collar 505 or some other portion of the casing string 515 is read by a sensor device (e.g., a sensor device 1178 of FIG. 11) in the form of a reader (e.g., a RF reader) as the wiper barrier plug assembly 550 travels down the cavity 520.

In this case, the trigger device 570 includes a controller (e.g., the controller 1174 of FIG. 11) that is in communication with a sensor device (e.g., a reader such as a RF reader) of the trigger device 570. The controller of the trigger device 570 can receive the measurement (e.g., a RF signal), evaluate the measurement (e.g., determine that the signal includes an expected ID, determine that the signal is at an expected frequency), and if the evaluation shows that the characteristic within the casing string 515 has been encountered (in this case, that the tag 525 has been identified), operate the expandable plug 560 to the expanded position. As of the time during the subterranean cementing operation captured in FIG. 5, the trigger device 570 has not passed and registered the tag 525, and the wiper barrier plug assembly 550 has forced the cement slurry 511 only a small way up the annulus 595. In this example, the trigger device 570 of the example wiper barrier plug assembly 550 does not include a back-up trigger, such as the back-up trigger 275.

The subsystem 698 of FIG. 6, which captures some amount of time (e.g., 30 seconds) after the time captured by the subsystem 598 of FIG. 5, includes all of the same components of the subsystem 598 of FIG. 5. At the point in time captured in FIG. 6, the wiper barrier plug assembly 550, propelled by the displacement fluid 512 pumped into the cavity 520 within the casing string 515, is located closer to the bottom plug 540. As a result, the cement slurry 511 is pushed further up the annulus 595. Also, the trigger device 570 has still not passed and registered the tag 525. As a result, the expandable plug 560 remains in the default position, allowing the wiper barrier plug assembly 550 to continue traveling down the cavity 520.

The subsystem 798 of FIG. 7, which captures some amount of time (e.g., 5 seconds) after the time captured by the subsystem 698 of FIG. 6, includes all of the same components of the subsystem 698 of FIG. 6. At the point in time captured in FIG. 7, the wiper barrier plug assembly 550, further propelled by the displacement fluid 512 pumped into the cavity 520 within the casing string 515, is located above, if not abutting against, the bottom plug 540. As a result, the cement slurry 511 is pushed even further up the annulus 595. More importantly, the trigger device 570, having just passed the tag 525, which was identified by the controller of the trigger device 570, has operated the expandable plug 560 from the default position to the expanded position.

By operating the expandable plug 560 into the expanded position, the expandable plug 560 extends outward in all directions so that the expandable plug 560 abuts against and creates a seal with the inner surface of the casing string 515. In so doing, the expandable plug 560 becomes fixed in place within the cavity 520 relative to the casing string 515. Also, the expandable plug 560 in its expanded position creates a pressure barrier and can remain anchored in place in spite of any pressure differential that may exist between the cavity 520 above the wiper barrier plug assembly 550 and in the cavity 520 below the wiper barrier plug assembly 550.

When the expandable plug 560 is operated into the expanded position by the trigger device 570, a pressure spike through the displacement fluid 512 above the wiper barrier plug assembly 550 within the cavity 520 can be measured at the surface (e.g., surface 108) by equipment (e.g., equipment 190). When the pressure spike is registered at the surface, the equipment pumping the displacement fluid 512 into the cavity 520 can be shut down. Also, one or more tests (e.g., a casing test, an in-flow test) can be performed at the surface (e.g., surface 108) using other equipment (e.g., part of equipment 190) to confirm that the expandable plug 560 of the wiper barrier plug assembly 550 is continuing to hold pressure.

FIGS. 8 through 10 show a cross-sectional view of a subsystem that includes yet another wiper barrier plug assembly 850 used in a wellbore cementing operation according to certain example embodiments. Referring to FIGS. 1 through 10, the subsystem 897 of FIG. 8 shows a point in time during the wellbore cementing operation. The subsystem 997 of FIG. 9 shows a subsequent point in time during the wellbore cementing operation relative to the time shown in FIG. 8. The subsystem 1097 of FIG. 10 shows a subsequent point in time during the wellbore cementing operation relative to the time shown in FIG. 9.

Many of the components of the subsystem 897 of FIG. 8 are substantially similar to the corresponding components of the subsystem 299 of FIG. 2 and the subsystem 598 of FIG. 5, except as discussed below. For example, the subsystem 897 of FIG. 8 includes a casing string 815 inserted into a wellbore 822. The wellbore 822 is defined by a wall 809 and is drilled into a subterranean formation 810. Also, in this case, at least some of the casing pipes of the casing string 815 have collars 805. The subsystem 897 of FIG. 8 also includes a float shoe 835 that has been set at or below the bottom of the casing string 815 within the wellbore 822, and one or more landing collars 830 that are set within the cavity 820 of the casing string 815 above the float shoe 835. All of these components (e.g., the float shoe 835, the collars 805, the landing collar 830) are substantially the same as the corresponding components (e.g., the float shoe 235, the collars 205, the landing collar 230) discussed above.

The subsystem 897 of FIG. 8 also includes a bottom plug 840 that is inserted within the cavity 820 of the casing string 815. The bottom plug 840 can be substantially the same as the bottom plug 240 discussed above. For example, the bottom plug 840 has a body 842 from which multiple wipers 845 extend outward. Also, the rupture disc (or other mechanical mechanism, such as a diaphragm) of the bottom plug 840 can break, as shown in FIG. 8, which opens a passage 844 along the height of the body 842 of the bottom plug 840. When the With the rupture disc broken, the cement slurry 811 can pass through the passage 844 in the bottom plug 840. Once the prepared volume of the cement slurry 811 is inserted into the cavity 820 of the casing string 815, the example wiper barrier plug assembly 850 is inserted atop the cement slurry 811 in the cavity 820 of the casing string 815, and displacement fluid 812 is subsequently pumped down (e.g., using equipment 190) atop the wiper barrier plug assembly 850.

The example wiper barrier plug assembly 850 is designed to push the cement slurry 811 down the cavity 820, eventually forcing the cement slurry 811 up the annulus 895 before the cement slurry 811 sets and hardens. As with the wiper barrier plug assembly 250 above, the wiper barrier plug assembly 850 of FIG. 8 includes a wiper plug 880, a trigger device 870, and an expandable plug 860. These multiple components are coupled to each other in any of a number of ways. In certain example embodiments, the multiple components of the wiper barrier plug assembly 850 are arranged vertically with respect to each other, as shown in FIGS. 8 through 10, but the arrangement of the components of the wiper barrier plug assembly 850 can vary.

The wiper plug 880 and the expandable plug 860 of the wiper barrier plug assembly 850 are substantially the same as the wiper plug 280 and the expandable plug 260 of the wiper barrier plug assembly 250. For example, the wiper plug 880 includes a body 882 from which multiple wipers 885 extend outward. The wipers 885 of the wiper plug 880 are oriented upward and have some amount of stiffness. In this way, as the wiper barrier plug assembly 850 is pumped down the cavity 820 ahead of the displacement fluid 812, none of the displacement fluid 812 is able to pass around the wipers 885 to mix with the cement slurry 811. Also, the body 882 of the wiper plug 880 is solid (e.g., does not have a cavity that traverses therethrough), and so the wiper plug 880 does not degrade or change state in such a way that allows the displacement fluid 812 to flow through and/or around the wiper plug 880 to mix with the cement slurry 811.

Also, the expandable plug 860 of the wiper barrier plug assembly 850 has a default position (as shown in FIGS. 8 and 9) and an expanded position (as shown in FIG. 10). In the default position, the expandable plug 860 avoids contact with the inner surface of the casing string 815 as the wiper barrier plug assembly 850 is moved down the cavity 820. In the expanded position, the expandable plug 860 extends outward in all directions so that the expandable plug 860 abuts against and creates a seal with the inner surface of the casing string 815. In so doing, the expandable plug 860 becomes fixed in place within the cavity 820 relative to the casing string 815. The trigger device 870 operates the expandable plug 860 from the default position to the expanded position, and so the trigger device 870 is communicably coupled to the expandable plug 860 to initiate such operation. In certain example embodiments, the expandable plug 860 has bi-directional slips so that, when in the expanded position, the expandable plug 860 remains in place relative to the casing string 815, even when differential pressure from above and below the wiper barrier plug assembly 850 within the cavity 820 exists.

The trigger device 870 of the wiper barrier plug assembly 850 is configured to determine when a trigger condition is met and, if so, operate the expandable plug 860 into the expanded position. The trigger device 870 in this case has two housing parts that include housing part 871 and housing part 872. In a default position, as shown in FIGS. 8 and 9, housing part 871 and housing part 872 are separated from each other and held apart from each other by a mechanical trigger 873. Examples of a mechanical trigger 873 can include, but are not limited to, a shear pin, rupture plate, and a shear ring.

When the wiper barrier plug assembly 850 contacts some immovable object, such as the bottom plug 840, the force of the impact overcomes the strength of (e.g., breaks, shears) the mechanical trigger 873. As a result, the mechanical trigger 873 breaks, and the housing part 871 collapses on the housing part 872. When the housing part 871 and the housing part 872 collapse together, as shown in FIG. 10 below, the trigger condition is met, and the expandable plug 860 immediately operates from the default position to the expanded position.

With the configuration of the trigger device 870 in this case, the equipment (e.g., equipment 190) at the surface (e.g., surface 108) may not slow the velocity of the wiper barrier plug assembly 850 (e.g., by slowing the pumping rate of the displacement fluid 812 into the cavity 820) to ensure that the impact of the wipe barrier plug assembly 850 against the bottom plug 840 is hard enough to overcome the strength of the mechanical trigger 873. In this case, there may not be any components (e.g., a sensor device, a controller) within housing part 871 or housing part 872 of the trigger device 870. While there are 3 collars 805 in this example, the trigger device 870 does not recognize them. Also, in this example, the trigger device 870 of the example wiper barrier plug assembly 850 does not show a back-up trigger, such as the back-up trigger 275, but such a back-up trigger can be included in the trigger device 870.

The subsystem 997 of FIG. 9, which captures some amount of time (e.g., 60 seconds) after the time captured by the subsystem 897 of FIG. 8, includes all of the same components of the subsystem 897 of FIG. 8. At the point in time captured in FIG. 9, the wiper barrier plug assembly 850, propelled by the displacement fluid 812 pumped into the cavity 820 within the casing string 815, is located closer to the bottom plug 840. As a result, the cement slurry 811 is pushed further up the annulus 895. Also, the distal component (in this case, the wiper plug 880) of the wiper barrier plug assembly 850 has still not run into the bottom plug 840. As a result, the expandable plug 860 remains in the default position, allowing the wiper barrier plug assembly 850 to continue traveling down the cavity 820.

The subsystem 1097 of FIG. 10, which captures some amount of time (e.g., 3 seconds) after the time captured by the subsystem 997 of FIG. 9, includes all of the same components of the subsystem 997 of FIG. 9. At the point in time captured in FIG. 10, the wiper barrier plug assembly 850, further propelled by the displacement fluid 812 pumped into the cavity 820 within the casing string 815, crashes into the bottom plug 840. As a result, the cement slurry 811 is pushed even further up the annulus 895. More importantly, the housing part 871 and the housing part 872 of the trigger device 870 collapse together with such force as to overcome the mechanical trigger 873, which operates the expandable plug 860 from the default position to the expanded position.

By operating the expandable plug 860 into the expanded position, the expandable plug 860 extends outward in all directions so that the expandable plug 860 abuts against and creates a seal with the inner surface of the casing string 815. In so doing, the expandable plug 860 becomes fixed in place within the cavity 820 relative to the casing string 815. Also, the expandable plug 860 in its expanded position creates a pressure barrier and can remain anchored in place in spite of any pressure differential that may exist between the cavity 820 above the wiper barrier plug assembly 850 and in the cavity 820 below the wiper barrier plug assembly 850.

When the expandable plug 860 is operated into the expanded position by the trigger device 870, a pressure spike through the displacement fluid 812 above the wiper barrier plug assembly 850 within the cavity 820 can be measured at the surface (e.g., surface 108) by equipment (e.g., equipment 190). When the pressure spike is registered, the equipment pumping the displacement fluid 812 into the cavity 820 can be shut down. Also, one or more tests (e.g., a casing test, an in-flow test) can be performed at the surface (e.g., surface 108) using other equipment (e.g., part of equipment 190) to confirm that the expandable plug 860 of the wiper barrier plug assembly 850 is continuing to hold pressure.

FIG. 11 shows a diagram of a wiper barrier plug assembly 1150 according to certain example embodiments. Referring to FIGS. 1 through 11, the wiper barrier plug assembly 1150 and its components of FIG. 11 are substantially similar to the wiper barrier plug assemblies and their corresponding components discussed above. In this case, the wiper barrier plug assembly 1150 includes an expandable plug 1160, a trigger device 1170, and a wiper plug 1180. The trigger device in this case includes a trigger 1173, an optional controller 1174, an optional counter 1177, one or more optional energy storage devices 1176, an optional back-up trigger 1175, and one or more optional sensor devices 1178.

The components shown in FIG. 11 are not exhaustive, and in some embodiments, one or more of the components shown in FIG. 11 may not be included in an example wiper barrier plug assembly 1150. Any component of the example wiper barrier plug assembly 1150 can be discrete or combined with one or more other components of the wiper barrier plug assembly 1150. Also, one or more components of the wiper barrier plug assembly 1150 can have different configurations. For example, one or more sensor devices 1187 can be disposed within or disposed on the wiper plug 1180. As another example, the timer 1177 can be part of the controller 1174.

The trigger 1173 of the trigger device 1170 can have a link 1168 to the expandable plug 1160 and, in some cases, the wiper plug 1180. Optionally, there can also be a link 1168 between the expandable plug 1160 and the wiper plug 1180 and/or between the trigger device 1170 and the wiper plug 1180, depending on the physical configuration of the trigger device 1170, the expandable plug 1160, and the wiper plug 1180 with respect to each other. A link 1168 provides a way for the trigger 1173 to operate the expandable plug 1160. A link 1168 can be or include one or more electrical wires. In such a case, the trigger 1173 can send an electrical signal or other form of electricity (e.g., a power surge) over the link 1168 to operate the expandable plug 1160 from the default position to the expanded position. Alternatively, a link 1168 can be or include a component that is mechanically-based, such as a pin, a hinge, a spring, or a detent. In such a case, the trigger 1173 can somehow manipulate the link 1168, which causes the expandable plug 1160 to operate from the default position to the expanded position.

The trigger device 1170 in this case has a housing 1172. Each of the components (including any sub-components) of the trigger 1170 can be disposed within the housing 1172, on the housing 1172, or remotely from the housing 1172. The trigger 1173 of the trigger device 1170 is configured to operate the expandable plug 1160. The trigger 1173 can be a mechanically-based and/or an electrically-based component. When the trigger 1173 is mechanically-based, one or more of the optional components (e.g., the controller 1174, a sensor device 1178, the energy storage device 1176) can be omitted from the trigger device 1170. An example of a mechanically-based trigger 1173 is the mechanical trigger 873 of FIGS. 8 through 10. A mechanically-based trigger 1173 can be integrated with one or more parts of the trigger device 1170, the expandable plug 1160, and/or the wiper plug 1180.

The controller 1174 of the trigger device 1170 communicates with and in some cases controls one or more of the other components (e.g., a sensor device 1178, the energy storage device 1176) of the trigger device 1170. The controller 1174 performs a number of functions that include receiving data, evaluating data, and sending commands based on evaluating data. The controller 1174 can include one or more of a number of components. Such components of the controller 1174 can include, but are not limited to, a control engine, a communication module, a timer, a power module, a storage repository, a hardware processor, memory, a transceiver, an application interface, and a security module.

Each sensor device 1178 includes one or more sensors 1179 that measure one or more parameters (e.g., position, azimuth, vibration, magnetic fields, pressure, flow rate, radiation, RF signals). The trigger device 1170 can include one or more sensor devices 1178. In some cases, a number of sensors 1179, each measuring a different parameter, and/or sensor devices 1178 can be used in combination to determine and confirm whether the controller 1174 of the trigger device 1170 should take a particular action (e.g., operate the expandable plug 1160).

Each of the one or more energy storage devices 1176 can be or include one or more batteries, supercapacitors, and/or other components that can store and subsequently release power. The power provided by the energy storage device can be of a type (e.g., direct current, alternating current) and of a level (e.g., 12V, 24V) that is used by the recipient component (e.g., the controller 1174) of the trigger device 1170. There can be any number of energy storage devices 1176. When an energy storage device 1176 includes battery units, the battery units can use one or more of any number of battery technologies. Examples of such technologies can include, but are not limited to, nickel-cadmium, nickel-metalhydride, lithium-ion, and alkaline. In certain example embodiments, each battery unit can be rechargeable.

The counter 1177 of the trigger device 1170 is configured to track the number of times that an event (e.g., detecting a magnetic field of a minimal strength, detecting a collar in the casing string) occurs. The controller 1174 can instruct the counter 1177 when to increment a count, and the counter 1177 can provide an active count to the controller 1177. In some cases, the controller 1174 can reset the count of a counter 1177. The counter 1177 can be configured to count multiple events individually and simultaneously at a particular point in time or for a range of times.

The back-up trigger 1175 of the trigger device 1170 is substantially the same as the back-up trigger 275 discussed above with respect to FIGS. 2 through 4. The back-up trigger 1175 can include its own controller that can act (e.g., instruct the trigger 1173 to operate the expandable plug 1160) independently of the controller 1174. In such a case, the controller of the back-up trigger 1175 can include some or all of the same components of and/or can have some or all of the same functionality as the controller 1174. Alternatively, the back-up trigger 1175 can communicate with the controller 1174 so that the controller 1174 can control (e.g., instruct the trigger 1173 to operate the expandable plug 1160) the back-up trigger 1175. The purpose of the back-up trigger 1175 is to ensure that the expandable plug 1160 operates in the event that the controller 1174 fails to do so within a reasonable amount of time.

The back-up trigger 1175 can include a timer that tracks an amount of time. The controller 1174 or the local controller of the back-up trigger 1175 can keep track of the time tracked by the timer of the back-up trigger 1175. When the time tracked by the timer of the back-up trigger 1175 reaches a time threshold value, as determined by the controller 1174 or the local controller of the back-up trigger 1175, the controller 1174 or the local controller of the back-up trigger 1175 instructs the trigger 1173 to operate the expandable plug 1160. If the expandable plug 1160 has already been operated under the normal process through the controller 1174, then the duplicative instruction to the trigger 1173 can have no effect on the expandable plug 1160 already in the expanded position. In some cases, the back-up trigger 1175 can receive power from the energy storage device 1176 in order to operate.

FIG. 12 shows a computing device 1218 according to certain example embodiments. FIG. 12 illustrates one embodiment of a computing device 1218 that implements one or more of the various techniques described herein, and which is representative, in whole or in part, of the elements described herein pursuant to certain example embodiments. For example, computing device 1218 can be implemented in the trigger device 1170 of FIG. 11 in the form of the controller 1174 (which can include a hardware processor, memory, and a storage repository, among other components). Computing device 1218 is one example of a computing device and is not intended to suggest any limitation as to scope of use or functionality of the computing device and/or its possible architectures. Neither should computing device 1218 be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the example computing device 1218.

Computing device 1218 includes one or more processors or processing units 1214, one or more memory/storage components 1213, one or more input/output (I/O) devices 1216, and a bus 1217 that allows the various components and devices to communicate with one another. Bus 1217 represents one or more of any of several types of bus structures, including a memory bus or a memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. Bus 1217 includes wired and/or wireless buses.

Memory/storage component 1213 represents one or more computer storage media. Memory/storage component 1213 includes volatile media (such as random access memory (RAM)) and/or nonvolatile media (such as read only memory (ROM), flash memory, optical disks, magnetic disks, and so forth). Memory/storage component 1213 includes fixed media (e.g., RAM, ROM, a fixed hard drive, etc.) as well as removable media (e.g., a Flash memory drive, a removable hard drive, an optical disk, and so forth).

One or more I/O devices 1216 allow a customer, utility, or other user to enter commands and information to computing device 1218, and also allow information to be presented to the customer, utility, or other user and/or other components or devices. Examples of input devices include, but are not limited to, a keyboard, a cursor control device (e.g., a mouse), a microphone, a touchscreen, and a scanner. Examples of output devices include, but are not limited to, a display device (e.g., a monitor or projector), speakers, outputs to a lighting network (e.g., DMX card), a printer, and a network card.

Various techniques are described herein in the general context of software or program modules. Generally, software includes routines, programs, objects, components, data structures, and so forth that perform particular tasks or implement particular abstract data types. An implementation of these modules and techniques are stored on or transmitted across some form of computer readable media. Computer readable media is any available non-transitory medium or non-transitory media that is accessible by a computing device. By way of example, and not limitation, computer readable media includes “computer storage media”.

“Computer storage media” and “computer readable medium” include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, computer recordable media such as RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which is used to store the desired information and which is accessible by a computer.

The computer device 1218 is connected to a network (not shown) (e.g., a LAN, a WAN such as the Internet, cloud, or any other similar type of network) via a network interface connection (not shown) according to some example embodiments. Those skilled in the art will appreciate that many different types of computer systems exist (e.g., desktop computer, a laptop computer, a personal media device, a mobile device, such as a cell phone or personal digital assistant, or any other computing system capable of executing computer readable instructions), and the aforementioned input and output means take other forms, now known or later developed, in other example embodiments. Generally speaking, the computer system 1218 includes at least the minimal processing, input, and/or output means necessary to practice one or more embodiments.

Further, those skilled in the art will appreciate that one or more elements of the aforementioned computer device 1218 is located at a remote location and connected to the other elements over a network in certain example embodiments. Further, one or more embodiments is implemented on a distributed system having one or more nodes, where each portion of the implementation (e.g., controller 1174) is located on a different node within the distributed system. In one or more embodiments, the node corresponds to a computer system. Alternatively, the node corresponds to a processor with associated physical memory in some example embodiments. The node alternatively corresponds to a processor with shared memory and/or resources in some example embodiments.

Example embodiments can be used to provide conventional cementing wiper plug functionality while acting as a barrier plug system to allow for safe removal of the plug container. Example embodiments can be used in land-based or offshore field operations. Example embodiments also provide a number of other benefits. Such other benefits can include, but are not limited to, less use of resources, time savings, and compliance with applicable industry standards and regulations. For instance, example embodiments eliminate the need for running a wireline operation to set a temporary bridge plug above the wiper plug (also sometimes called a tail plug) in the wellbore.

Although embodiments described herein are made with reference to example embodiments, it should be appreciated by those skilled in the art that various modifications are well within the scope and spirit of this disclosure. Those skilled in the art will appreciate that the example embodiments described herein are not limited to any specifically discussed application and that the embodiments described herein are illustrative and not restrictive. From the description of the example embodiments, equivalents of the elements shown therein will suggest themselves to those skilled in the art, and ways of constructing other embodiments using the present disclosure will suggest themselves to practitioners of the art. Therefore, the scope of the example embodiments is not limited herein. 

What is claimed is:
 1. A wiper barrier plug assembly comprising: a wiper plug comprising a wiper plug body and a plurality of wipers extending from the wiper plug body, wherein the plurality of wipers is configured to contact an inner surface of a casing string disposed in a wellbore; an expandable plug; and a trigger device comprising a trigger that is communicably coupled to the expandable plug, wherein the wiper plug, the expandable plug, and the trigger device are mechanically coupled together, wherein the trigger device is configured to: detect a trigger condition while the trigger device is pumped down a cavity of the casing string formed by the inner surface; and operate, upon detecting the trigger condition, the expandable plug from a default position to an expanded position, wherein the expandable plug, when in the expanded position, is configured to abut against an inner surface of the casing string and to prevent the expandable plug from moving relative to the casing string.
 2. The wiper barrier plug assembly of claim 1, wherein the trigger device further comprises a sensor device that is configured to measure a parameter, wherein the trigger condition comprises a measurement, made by the sensor device, of the parameter that exceeds a threshold value.
 3. The wiper barrier plug assembly of claim 2, wherein the sensor device is configured to identify at least one individual casing pipe within the casing string, wherein the trigger condition is based on identifying the at least one individual casing pipe.
 4. The wiper barrier plug assembly of claim 3, wherein the sensor device detects a radioactive source within the at least one individual casing pipe, wherein the trigger condition is based on identifying the radioactive source.
 5. The wiper barrier plug assembly of claim 3, wherein the sensor device comprises a radio frequency (RF) identifier that identifies a RF tag, wherein the trigger condition is based on the RF identifier identifying the RF tag embedded in the at least one casing pipe of the casing string.
 6. The wiper barrier plug assembly of claim 3, wherein the at least one individual casing pipe is a plurality of individual casing pipes, wherein the trigger device further comprises a counter in communication with the sensor device, wherein the trigger condition occurs when the counter exceeds a threshold value.
 7. The wiper barrier plug assembly of claim 6, wherein the trigger device further comprises a controller that evaluates the measurement made by the sensor device and a count maintained by the counter.
 8. The wiper barrier plug assembly of claim 1, wherein the trigger condition is based on making contact with a bottom plug disposed in a cavity formed by the casing string.
 9. The wiper barrier plug assembly of claim 8, wherein the trigger device comprises multiple housing parts, wherein the trigger condition occurs when the multiple housing parts collapse together when the bottom plug is contacted.
 10. The wiper barrier plug assembly of claim 1, wherein the trigger device further comprises a timer that measures a threshold amount of time by which the trigger condition occurs.
 11. The wiper barrier plug assembly of claim 1, wherein the trigger device is disposed between the wiper plug and the expandable plug.
 12. The wiper barrier plug assembly of claim 1, wherein the expandable plug comprises a cast iron bridge plug.
 13. The wiper barrier plug assembly of claim 1, wherein the expandable plug comprises a composite plug.
 14. A system for preparing a casing string in a wellbore for cement, the system comprising: a landing assembly disposed at a distal end of the casing string, wherein the landing assembly provides a channel for a first fluid to flow from a cavity of the casing string toward the surface through an annulus formed between an outer surface of the casing string and a wellbore wall; a bottom plug affixed to an inner surface of the casing string above the landing assembly, wherein the bottom plug has a flow path that traverses therethrough and through which the first fluid flows; and a wiper barrier plug assembly disposed in the cavity of the casing string, wherein the wiper barrier plug assembly comprises: a wiper plug comprising a wiper plug body and a plurality of wipers, wherein the wiper plug provides a barrier between a first fluid disposed below the wiper plug and a second fluid disposed above the wiper plug; an expandable plug operable from a default position and an expanded position; and a trigger device comprising a trigger, wherein the wiper plug, the expandable plug, and the trigger device are mechanically coupled together, wherein the trigger device: detects a trigger condition while the wiper barrier plug assembly is pumped toward the bottom plug by a pumping system; and operates, upon detecting the trigger condition, the expandable plug from the default position to the expanded position, wherein the expandable plug, when in the expanded position, is configured to abut against the inner surface of the casing string prevents the expandable plug from moving relative to the casing string.
 15. The system of claim 14, wherein the first fluid comprises a cement slurry, and wherein the second fluid comprises displacement fluid.
 16. The system of claim 15, wherein the expandable plug, when in the expanded position, allows the cement slurry to cure in the annulus while preventing the displacement fluid from contaminating the cement slurry.
 17. A method for setting a wiper barrier plug assembly when cementing a casing string in a wellbore, the method comprising: detecting, by a trigger device of the wiper barrier plug assembly, a trigger condition while the wiper barrier plug assembly is pumped through a cavity of the casing string toward the bottom plug by a pumping system; and operating, by the trigger device upon detecting the trigger condition, an expandable plug of the wiper barrier plug assembly from a default position to an expanded position, wherein the expandable plug, when in the expanded position, abuts against an inner surface of the casing string and prevents the wiper barrier plug assembly from moving relative to the casing string, wherein the wiper plug, the expandable plug, and the trigger device are coupled to each other.
 18. The method of claim 17, wherein detecting the trigger event comprises determining, using a controller of the trigger device, when a number of casing collars as measured by a sensor device of the trigger device, exceeds a threshold value.
 19. The method of claim 17, wherein detecting the trigger event comprises determining, using a controller of the trigger device, when a radio frequency identification signal has been received by a sensor device of the trigger device.
 20. The method of claim 17, wherein detecting the trigger event comprises determining, using a controller of the trigger device, when an amount of time, as measured by a timer, exceeds a threshold value. 